zap technology. arrival. with hertz gold plus rewards, you skip the counters, the lines, and the paperwork. zap. it's our fastest and easiest way to get you into your car. it's just another way you'll be traveling at the speed of hertz. >>> this is fox news channel's continuing coverage of the boston bombing. i'm shepard smith on boylston street, and the chaos that followed played out in front of so many cameras. possible by what the bomber wanted. videos of people crossing the finish line and then a horrific crime. >> where are we supposed to go? >> they're taking down madly. all the stuff from the marathon. [sirens] >> shepard: cassidy who took this does video for a living. she's with us, and bruce as well, a witness who was there at the time it hand. cassityie, you were taking video of a friend? >> one of my coworkers was about to finish the race but he actually had -- a few minutes before but at first i was bummed that i missed hem bought i wanted to tweet out a picture of him finishing the race so i went